The present disclosure relates generally to image sensor devices and, more particularly, to an apparatus and method for reducing optical crosstalk in image sensor devices.
An image sensor provides a grid of pixels which may contain photosensitive diodes or photodiodes, reset transistors, source follower transistors, pinned layer photodiodes, and/or transfer transistors for recording intensity or brightness of light. The pixel responds to the light by accumulating photo-charges—the more light, the more the photo-charges. The charges can then be used by another circuit so that a color and brightness can be used for a suitable application, such as a digital camera. Common types of pixel grids include a charge-coupled device (CCD), a complimentary metal oxide semiconductor (CMOS) image sensor (CIS), an active-pixel sensor (APS), and a passive-pixel sensor.
In order to capture color information, image sensors may employ a color filter layer that incorporates several different color filters (e.g., red, green, and blue), and are positioned such that the incident light is directed through the filter via an array of micro-lens. However, the micro-lens may exhibit poor light control ability at a region between adjacent micro-lens. That is, incident light traveling through this region may not be directed to the appropriate pixel for processing. This may result in optical cross-talk between adjacent pixels and thus, may lead to poor device performance.
Therefore, what is needed is a simple and cost-effective apparatus and method for reducing optical cross-talk in image sensor devices.